AIDS care programs are also likely to pay for themselves in developing countries through increased labor productivity and averted orphan and patient care costs, according to a study published last month in the open-access journal PLoS ONE.

My reader writes, it strikes me that if you have free migration and a high turnover of people in a society or nation, society becomes an open-access resource, and you will end up with a kind of tragedy of the commons decision making which puts too much store on the short-term.

That is, when a culture is not too averse to open trade, changes in political structure can push the polity in the direction of what he calls an "open-access order," in which competition for political power and economic well-being is relatively fair and open.